1. Field of the Invention
The present invention relates generally to a correction circuit and more particularly, to a single-stage power factor correction circuit that comes with a switch for facilitating positive and negative half cycles to provide a conducting path, so that the current just needs to pass through two rectifiers to lower the temperature of the power supply.
2. Description of the Related Art
A single-stage power factor correction circuit is usually used in a high-performance power supply for improving power factor. In conventional single-stage power factor correction circuits, a loop is formed by passing current through three rectifiers at a positive half cycle or a negative half cycle by means of the ON and OFF of a metal oxide field effect transistor (MOFET).
However, the aforesaid conventional single-stage power factor correction circuit has the drawback that the current has to pass through three rectifiers to form a loop regardless at a positive half cycle or at a negative half cycle, and thus causing a higher conduction loss and increasing the temperature of the power supply.
In view of the aforesaid problem, the present invention filed a utility model to Intelligent Patent Office of Ministry of Economic Affairs. Republic of China on May 9, 2006, entitled “Single-stage power factor correction circuit” (Patent number M301459, equivalent to U.S. application Ser. No. 11/493,879, now allowed). This invention is functional, however it is still not perfect in reduction of the number of component parts and lowering of heat due to current stress.